Stoker mechanism



Sept. 29, 1942. CHALKER I S TOKER MECHANISM Filed May 2, 1938 l5 4/ 2g CENTER LINE OF I L I I L OCOMO 7/ V5 & TEND INVENTOR A/berl R. Cha/lrer 4/ I, W CENTER LINE 0F LOCOMOT/VE a TENDER v ATT NEY Patented Sept. 29, 1942 STOKER MECHANISM Albert R. Chalker, Bellevue, Pa., assignor to The Standard Stoker Company, Incorporated. a.

corporation of Delaware Application May 2, 1938, Serial No. 205,394

4 Claims.

My invention relates generally to stokers and more particularly to locomotive stokers of the type that convey fuel from a source of supply, as from the tender, to the firebox through the usual firing opening in the locomotive boiler backhead, from which point the fuel is scattered over the fire by a pressure fiuid blast.

An object of my invention is to provide a Stoker mechanism, the delivery end of which is constructed in a novel and advantageous manner to raise the firing height.

More specifically the invention contemplates the provision of a novel distributor member so constructed and arranged with a stoker fuel delivery conduit to furnish a high firing height above the furnace grate.

Another object of the invention is to provide a novel distributor member so constructed and arranged with a stoker fuel delivery conduit that more fuel will be deposited on one side of the upper surface of the plate-like forwardly extending portion of the distributor member than on the upper surface of the other side thereof.

These and other objects, such as the particular construction of theparts and their novel relation one with another, will be apparent from the following description when read in connection with the accompanying drawing, in which- Fig. 1 is a fragmentary sectional plan View through the firing opening of the boiler backhead showing the novel stoker construction applied thereto;

Fig. 2 is a side elevation of the stoker with parts, broken away and shown in section and applied to a locomotive backhead shown in vertical medial section;

Fig. 3 is a central vertical longitudinal section through the locomotive boiler backhead with the stoker applied thereto and shown in similar section; and

Fig. 4 is a fragmentary sectional plan view through the firing opening of the boiler backhead showing a stoker applied thereto and having a modified form of distributor.

A locomotive is indicated generally by the numeral l0 and comprises a firebox H and a boiler backwall [2 having a firing opening l3 therein. The locomotive cab deck l4 extends rearwardly from the backwall l2 below the firing opening l3.

Only so much of the stoker S has been shown as is essential to a complete understanding of the invention. Means, well known in art, advances fuel from a source of supply, as from a tender fuel bin (not shown), to the locomotive. An inclined riser conduit l5 extends upwardly and forwardly from a position rearward of and below the level of the firing opening l3 and communicates at its upper end with the firing opening. Ihe riser conduit [5 is rigidly secured to the backwall l2 in any suitable manner. A screw conveyor l6 advances fuel through the riser conduit 15 to the firing opening IS.

A rectangular shaped casing, indicated generally at ll, formed with the riser conduit l5 embraces the lower portion of the firing opening 13. The casing ll com-prises a rear wall [8 spaced from the plane of the backwall l2, and side walls [9 and 20 extending forwardly from the rear wall I8 to the plane of the backwall, one at each side of the firing opening. The casing H is secured to the backhead through the angles 2|. The upper portion of the firing opening is provided with a power operated firedoor 22, which is preferably of the type comprising a pair of pivoted door members 23 and 24 arranged to swing upwardly and laterally and mounted in any well known manner on the firedoor frame 25 which embraces the upper portion of the firing opening [3. The door members 23 and 24 form in effect continuations of the side and rear walls of the casing [1, the walls forming the door members converging as they extend upwardly. The lower rearward edges of the door members are received in a groove 26, and the shoulder 21 formed on the casing ll prevents the door members from being blown out rearwardly should an explosion occur within the firebox.

The riser conduit I5 has a distributor casting 28 secured to the lower forward end thereof in a suitable manner, as by means of bolts 29, 29a. The casting 28 comprises a concave wall composed of a plurality of triangular shaped faces, including front face 33, side faces- 34 and the opposite side faces 35, all disposed at a greater angle to the horizontal than the riser conduit l5 forming at the forward end of the riser conduit an upturned spout 30. The upper edges of the triangular faces 33, 34 and 35 lie in a common horizontal plane forming a spill edge Bil over which the fuel advanced by the screw conveyor I6 will fall. A vertical wall 32 depends from and follows the contour of the spill edge of the concave wall or spout 39.

Included between the concave wall or spout 30 and the depending wall 32 is a chamber 36 arranged to receive steam from a suitable source of supply by the pipe 31. The vertical faces of the depending wall 32 are provided with a plurality of jet passages communicating with the steam chamber 36 and arranged in an upper row 38 and a lower horizontal row 68.

A fuel distributor plate 39 extends forwardly from the lower edge of the depending wall 32 and is arranged to receive the fuel dropping over the spill edge 60 of the concave wall or spout 30. Steam emitted from the jet passages 38 and 68 project the fuel across the plate 39 into the firebox. The vertical depending wall 32 is provided with the vertical spaced projections 40 terminating at their lower ends just above the lower row of jets 68 and through which projections the upper row of jets 38 extends. The surface of the plate 39 declines slightly from the horizontal as it extends forwardly, and the plane of the tops of the ribs 4| formed on the plate 39 inclines slightly from the horizontal. This construction permits the fine coal to drop between the projections 40 onto the plate 39 in front of the lower row of jets 68 which are directed slightly downwardly and which project the fine fuel forwardly between the ribs 4|. The coarse fuel drops into the zone of action of the upper row of jets 38 and is projected along the ribs M. The upper row of jets 38 that projects the coarse fuel thus forms a blanket over the finer fuel particles and prevents to a large extent escape of finer fuel particles over the firebox arch.

It is well known that a helicoid screw will deliver more coal to one side of its axis than to the other. Thus a screw, the flights of which are so wound to advance fuel when rotated in a clockwise direction, as viewed in the direction of fiow will deliver most of its charge to the left side of its axis. Referring particularly to Fig. 1, it will be seen that the screw It will deliver most of its charge toward the side of the firebox marked L. In the constructions shown in the prior art, the discharge end of the riser conduit is located centrally of the sides of the firebox and in order to prevent the side L of the firebox from receiving an oversupply of fuel, vanes or dividers are generally employed to direct more fuel to the side of the firebox marked R in order to obtain an even supply of fuel to both sides of the firebox. In the present construction, with the discharge end of the conduit located more to the side R of the firebox, vanes and dividers are not necessary since there is a greater area at the side L of the discharge end of the conduit than to the side R thereof which is to be supplied with fuel, and more fuel is therefore necessary on the side L to provide even distribution over the entire firebox.

A number of factors determine just how much more coal is delivered to one side or the other of the screw, as for example, how far the screw in the riser conduit extends, the angularity of the screw with respect to the vertical medial plane of the firebox, and other factors. As best shown in Fig. 1 the rearward portion of the riser conduit I5 is angularly disposed with respect to the vertical medial plane of the locomotive while the forward portion thereof is parallel to the said plane. The screw conveyor I6 is in axial alinement with the axis of the rearward portion of the riser conduit so that the terminal portion of the screw conveyor is nearer the right side of the spout 30 than the left side thereof and will cause more coal to be delivered to the right side of the spout than if the terminal portion of the screw conveyor were disposed centrally of the spout. Thus, if it is necessary to provide more fuel on the side L of the firebox than is provided by the preferred construction, a modified form of the distributor member, as shown in Fig. 4, may be employed.

The construction shown in Fig. 4 differs from the preferred construction only in the configuration of the concave wall or spout. The plurality of faces 34 of the preferred form of construction being formed as a single face 50. As a result the slope of the face 50 is steeper than the slope of faces 35 and more fuel will be forced over the spill edge of the faces 35 than over the spill edge of the face 50. As in the preferred form of the invention, the terminal portion of the screw conveyor is nearer the right side of the spout than the left side thereof.

This is a continuation in part of my application Serial No. 21,721 filed May 16, 1935, now Patent No. 2,119,941, granted June 7, 1938.

I claim:

1. In combination with a furnace having an upright wall with a firing opening therethrough, a tubular stoker conduit extending in a general upward and forward direction and at its delivery end communicating with said firing opening, said conduit having its bottom inside surface substantially straight along the medial vertical plane of the conduit, the lower forward end of said conduit being provided with an upturned delivery spout disposed at one side of the medial vertical longitudinal plane of the furnace, and means in said conduit for conveying fuel through the conduit and the delivery spout, the inside surface of said spout being concave in transverse cross section and having a steeper slope on that side more remote from said medial vertical longitudinal plane of the furnace.

2. In combination with a furnace having an upright wall with a firing opening therethrough, a tubular stoker conduit extending in a general upward and forward direction and at its delivery end communicating with said firing opening, said conduit having its bottom inside surface substantially straight along the medial vertical plane of the conduit, the lower forward end of said conduit being provided with an upturned delivery spout disposed at one side of the medial vertical longitudinal plane of the furnace, and means in said conduit for conveying fuel through the conduit and the delivery spout, the inside surface of said spout being concave in transverse cross section and having a steeper slope on that side more remote from said medial vertical longitudinal plane of the furnace, the spill edge of said spout lying in a horizontal plane.

3. In combination with a furnace having an upright wall with a firing opening therethrough a tubular stoker conduit extending in a general upward and forward direction and at its delivery end communicating with said firing opening, a distributor member, said member having a slopng concave rear wall forming an upturned flarmg delivery spout at the lower forward end of sa1d conduit and disposed at one side of the medial vertical longitudinal plane of the furnace means for advancing fuel through said conduit and said spout, the inner wall portion of the spout at one side of its longitudinal vertical medial plane having a more gradual slope than the inner wall portion at the other side of said plane said spout being arranged with its said more .gradually sloped side nearer the medial vertical longitudinal plane of the furnace than its steeper sloped side, said member also having a wall depending from and following the contour of the upper edge of said concave rear Wall and formed with a chamber between said depending wall and concave rear wall, said depending wall being provided with transversely spaced orifices communicating with said chamber, and means for securing said distributor in fixed relation with said conduit.

4. In combination with a firebox having an upright wall provided with a firing opening, a stoker riser conduit mounted exteriorly of the firebox communicating at its discharge end with the firing opening, the discharge end of said conduit being disposed at one side of the longitudinal medial plane of the firebox, a fuel conveying screw within said conduit terminating adjacent the upper end thereof, the flights and direction of rotation of said screw being arranged to deliver the greater portion of its charge on that side of its axis toward the longitudinal medial plane of the firebox, fuel distributing means including a plate extending in the firebox, a delivery fioor extending forwardly from the forward end of said riser conduit at a greater inclination with respect to the horizontal than said riser conduit, the forward end of said delivery floor forming a ledge over which fuel spills onto said plate, said ledge being spaced a greater distance from the axial terminus of said screw on that side thereof receiving the greater charge of fuel.

ALBERT R. CHALKER. 

